Impious

This.

Those Tantric subs OEM'd by TC or Fi ? I didn't realize anyone else had the rights to those baskets.

Funny, was supposed to go semi-formal dress shopping for my daughter this weekend....but apparently she's "bloated" so she wants to hold off until next weekend now. Wants to go with Dad not because I'm more fun but I'm a bigger pushover, so she'll get more out of me than she would her mom.

I think I've read some people had noise issues with the NVX. Given their price point* is the lowest of anyone using that board I would suspect they use lower quality internal parts than some of the more expensive amps using the same board (Hertz, Polk), but probably pretty similar to the PPI/Soundstream variant. *I was comparing how much you can get them for at places like Sonic, not MSRP.

Both. If the sub is wired to a nominal .5ohm load then there will be frequencies where the actual load is higher than .5ohm and also frequencies where the load could be equal to or less than .5ohm. Along with this as the coil heats up the impedance of the coil is going to increase as well. So, while it's true that the impedance could be 1ohm or higher at certain times, it's also possible for it to be .5ohm or less. How well the amplifier handles these lower impedance loads, the impedance curve of the system (driver + enclosure) and how well the coil dissipates heat to limit (or not limit) the rise in impedance with applied power are all going to factor in. The difference in power is not going to be audible while the additional strain to the amplifier and electrical system is going to be substantial, making it useless/pointless to do in a daily system. As Shizz said, for competitors where every .1db matters and pushing equipment to their maximum is commonplace it can be beneficial. For a daily driver system it's completely unnecessary and pointless with no real benefit.

I will simply say this. You can do all of the internet research you want, but at the end of the day it all boils down to the validity of the source/information. Be careful of your source. History shows us that most of the conspiracy theorists end up using misinformation and nonfactual information. 9/11 for example....if you read through enough conspiracy theory websites they'll have all kinds of facts, evidence, authorities, etc verifying their claims. But if you really look with scrutiny at the information they're presenting, it's always misrepresented, nonfactual, subjective and interpretive with nothing to really support them outside of other conspiracy theorists. I'm not saying people should be sheep and take everything the government or mass media say for granted. I think questioning, investigating, etc is a productive endeavor as the government (corporations, media, et al) do make bad decisions, they do deceive, and it can get out of control if we don't question, investigate and keep them in check. But validity and reliability are critical in this pursuit.

So this is the new 9/11 then, eh?

Based on the power ratings you should get about 500w out of the amp @ 3ohm which would be sufficient.

http://diysubwoofers.org/misc/portcal.htm About half way down the page gives a good formula to use to estimate the minimum port area you should have.

Wish the best for your family and daughter. Donations will definitely be going to a worthy cause.

Pretty sure ID has always rebadged their compression drivers. I believe they claim slight modifications were made to them, but on the whole I'd expect them to perform nearly identically to the original product.

Absolutely no reason that amplifier shouldn't be able to sufficiently power that subwoofer as long as everything is properly setup

Can this method be used for setting the LPF? Yes, method is exactly the same except you would obviously want to have the LPF set at maximum instead of minimum when measuring the first voltage and then turn the knob down until you achieve the calculated target voltage. Will also say that the .707 only works properly if the filter is a butterworth. If it's LR then the multiplier would be different.

Shizz and Stefan are correct, there's no such thing as "box rise". Impedance simply varies with frequency and while yes the enclosure does affect the shape of the impedance curve it's not the only factor. Impedance will vary with frequency due to the behavior of the driver, it will also increase as power is applied to the driver due to heat, etc. Another thing people confuse is the difference between Re and nominal impedance. Re, also known as DCR or DC resistance, is the resistance of the coil with a DC signal. Re is one of the Thiele Small parameters listed by the manufacturer. It is typically a bit less than the rated nominal impedance of the coil. For example, a 2ohm voice coil might have a Re of 1.6ohm. So some uneducated fellow sees this and says his amplifier is wired to 1.6ohm and that "box rise" causes the impedance of the driver to be 2ohm. He would be wrong. Since, as was mentioned, impedance varies due to several different factors over the entire audio bandwidth there is no one "impedance" to call a driver. A 4ohm driver isn't 4ohm at every frequency. Nominal impedance is basically an average value of the load presented to the amplifier over the intended operating bandwidth (outside of resonance, where there is a huge peak in impedance). Re and nominal impedance are not the same thing, and generally speaking when you hear someone say they are "wired" to odd values like .7, 1.6, etc it's because they don't understand the difference between Re and nominal impedance.

http://fortwayne.craigslist.org/cto/3505988430.html This mother fucker needs shot.

10's are not "more punchy" than 12's. That's a myth and completely wrong not as a matter of opinion but a fact of physics. And while 12's generally offer greater displacement which could potentially give them better low frequency extension there are many more factors at play. If you aren't happy with the performance of your current subs the first thing you should investigate is building a new enclosure to achieve your desired performance before spending money on new equipment.

Nope.

Do you already have the subs? Seems like you have a decent amount of space down there....should be able to fit something larger than 8's if you went down-firing.

The Dcon would be much happier in a ported enclosure. If you have the space I would absolutely do that before you buy anything new.

I have no idea what you just said.

Could have been worse. Could have showed up 10 minutes late and had to sit at a lab table against the wall only to realize you were in the wrong classroom anyways.

I can't find it now and don't know if the new amps are the same way, but the Power series a generation or two ago had an FR that had a 1.5db or 3db peak (can't remember exactly) in the response in the bass and again in the treble. So if the output was rated at 0db but they measured for the birthsheet at one of the "peaks" then the power would inherently show 50-100% higher on the birthsheet.

By "no input signal from the headunit", have you physically disconnected the RCA's from the amplifiers input ? My first thought is turn on pop, which is caused by the amplifier turning on before the HU is completely on. If this is the case physically removing the RCA's from the amp would solve the problem....Obviously not a long term solution, but it would tell you if that is indeed the problem.

The folks at JL are generally pretty smart fellas, if they recommend 2.375cuft I'd imagine the driver would perform pretty well. That said you can adjust net volume and tuning to better match your goals if your goals differ from what JL's goals when recommending the 2.375cuft enclosure. Yes, glue them together. As long as the sheets properly bond with the glue they should not rattle loose. Use bracing within the enclosure as well. Changing the dimensions is fine, however the change in port height will however require you adjust either width to keep port area the same, or adjust port length to keep tuning the same. If I understand your question correctly no it doesn't matter. If you are going ported, I would recommend sticking with a standard slot port. Given this is going in a smaller sized truck with limited space is a ported enclosure a necessity? Might be easier to go sealed and still get good performance especially if you are limited on space.

That's a pretty damn serious motor you are designing there. Also very versatile, I could think of a couple fun things to do with it. What diameter spider is that going to use to match the throw of the motor?